1. Field of the Disclosure
This disclosure relates to an air conditioning system, and particularly, to an air conditioning system capable of communicating data of an indoor unit or outdoor unit using a low frequency signal via a refrigerant pipe, and a communication method thereof using a refrigerant pipe.
2. Background
In general, an air conditioning system is provided with an indoor unit and an outdoor unit to drive a cooling or heating cycle in response to a user's demand. Here, the indoor unit and the outdoor unit are connected to each other via a refrigerant pipe.
Recently, a multi-type air conditioning system, which includes a plurality of multi air conditioners each having an outdoor unit for controlling distribution and circulation of a refrigerant, and indoor units sharing the outdoor unit to discharge air into each room, and a controller for connecting and controlling the plurality of air conditioners.
For example, as shown in FIG. 1, an air conditioning system includes one outdoor unit 200, and a plurality of indoor units 100A to 100D connected to the outdoor unit 200 via a refrigerant pipe 300.
Meanwhile, an air conditioning system may circulate a fluid, namely, a refrigerant, sequentially via a compressor, a condenser, an expansion valve and an evaporator, or in the reverse sequence, thereby performing cooling or heating for an indoor room. The refrigerant is refilled (supplemented) as much as being appropriate for a capacity of the air conditioning system upon installation of the air conditioning system. However, due to passage of time, namely, after prolonged use of the air conditioning system, the refrigerant is consumed, thereby causing the lack of refrigerant in the air conditioning system. If the refrigerant is insufficiently left, efficiency of the air conditioning system is lowered. So, the refrigerant should be refilled to maintain an appropriate level. Accordingly, to maintain an appropriate amount of refrigerant, which is consumed, a technique for constantly maintaining the amount of the refrigerant by injecting the refrigerant according to the capacity of the air conditioning system has been introduced.
The refrigerant pipe for connecting the indoor unit to the outdoor unit is installed within a building or the like in advance. If the number of outdoor units and indoor units is increased or the outdoor unit and the indoor unit are located at a farther distance, the length of the refrigerant pipe becomes longer, which increases the number of branches.
Hence, the air conditioning system and pipe communication method thereof according to the related art cause the following problems. That is, if a long pipe or a pipe with many branches is used, the outdoor unit and the indoor unit are located at a far distance from each other, which causes a communication signal to be weak (attenuated), thereby lowering reliability of the pipe communication.
Furthermore, in the air conditioning system and pipe communication method thereof according to the related art, upon performing communication via the refrigerant pipe, a signal frequency band is not concerned, thereby causing occurrence of noise interruption, attenuation of a signal strength and signal radiation.